Absorption refrigerating apparatus



T. M. ELFVING ET AL ABSORPTION REFRIGERATING APPARATUS FiledOct. 1.2, 1933 sqft. 2,1, 1937.

2 Sheets-Sheet 1 JMD fam

Patented Sept. 21, 1937.

.UNITED STATES PATENT oFFicE Y 'more Martin Euving and nuns Hyland, stockholm, Sweden, assignors, by mesne assignments, to Servel, Inc., Dover, Del., a corporation of Delaware Application Gctober 12, 1933, Serial No. 693,278

. In Sweden October 20, 1932 scmms.

'Ihe present invention relates to intermittently working absorption refrigeratingapparatus -and provides .novel and simple means for regulating and controlling the heating andcooling of the' boiler-absorbers being carried out vby forces gen- 16 erated inside the apparatus.

The invention will be more closely described in conjunction with the accompanying drawings, of which Figure 1 shows a front section of a system comprising two co-operating apparatus provided 9 with a cooling system in common for both of the boiler-absorbers. Figure 2 shows a side view of the system shown in Figure 1. Figure 3 shows a single intermittent apparatus according to. the invention. Figure 4 shows-a modification of the igure.` 'I'he cooling pockets I8 and I9 communicate through pipes 23 and 24 `with a condenser 25 forming a. separate cooling system without fluid communication with the absorption systems proper, said separate system being partially filled with a volatile liquid such as ammonia for transfer of heat from the boiler-absorbers to the condenser 25. Each cooling pocket may alternative- 1y be provided with its ownseparate cooling system. The boiler-absorbers I and l `and the separate cooling system are rigidly connected with each other. Together they are movably arranged on bearings 28 in bracket 29. I The conduits 2 and 8 are relatively small in diameter and are run in spirals or loops; 26 and 2l respectively, so as to be suiciently flexible to permit the boiler-absorbers I1 and 1, et cetera,

to Amove freely on their bearings.A "Ihus the boiler-absorbers with the separate cooling system can be set in different inclinations as indicated in the gure. When reversing the inclination of` the condensing element the collecting place for the condensate is shifted from one of the aforementioned cooling pockets to the other. The mer- 25 apparatus shown in Figures 1 and 2. .cury switch `is disposed on the movable system 25 'I'he units shown in Figures l and 2 consist of and adapted to switch the heat supply from one two separate but interdependent, intermittent of the boiler-absorbers to the other simultaneousl absorption systems. The rst of said systems ly with the reversing of the condensate collection consists of a boiler-absorber I, communicating by place in the separate cooling system. In the case 30 means of a pipe 2 with a condenser 3 from which a conduit 4 leads to a vessel 5. An evaporator coil 6 communicates with said vessel. The second system consists of a boiler-absorber'l communicating by means of a conduit 8 with a conv.denser 9. 'The condensers of the two systems are crum point of the movable system should be lobuilt together and adapted to be cooled by cooling cated 'a little below the center of gravity of said flanges I0 in common. From condenser 8 a consystem so that a certain Apredetermined vleverage duit II extends to a vessel |21' which communiis necessary for moving the system from one excates withv an evaporator coil I3. The evaptreme position to the other. The power for reu orator coils 6 and I; surround an ice tray compartment Id and are also provided withcooling anges I5. The boiler-absorbers are provided with central tubes If and I'I respectively, which are surrounded by intermediate tubes, forming cooling pockets I8 andis. The tubes are pro vided with flanges P, between which a solid .ab-

sorbent'is stored. The absorbent may consist of calcium chloride, strontium chloride. silicav gel, or other solid absorbing oradsorbing substances w or mixtures thereof. The vessels 5 and I2 arepreferably insulated from each other and from the surroundings. The boiler-absorbers I and 'I are to be alternatingly heated-withelectric heating elements 2li and 2 i, which are connected' with athree-waymercury switch 22 as shown in the -ing system has now such an inclination that the collectingplace, for the condensate will be the cooling pocket of the boiler-absorber 1, which consequently will be cooled, the heat being dissipatedinto the air due to the evaporation-recondensation of the condensate. Itis being amumed that the boiler-'absorber l has been recently heated and that absorption is now going on there. Thus the weight of the boiler-absorber 'l is 'steadily increasing. At the same time the expulsion of refrigerant from boiler-absorber l results in a decrease of weight. When the weight difference between the boiler-absorbers has reached a certain predetermined value, the movable system tilts over to the other extreme position, so that the heat supply is switched over from boiler-absorber I to boiler-absorber 1. At the same time the cooling action of the separate secondary system is switched towards boiler-absorber l. By this method a simple and reliable automatic cooperation of the two absorption systems is accomplished so that the cooling cycles will closely follow upon one another, giving a semi-continuous refrigeration effect as a result.

The weight difference necessary for reversing the movable system should be chosen with regard to the amount of absorbent in the boilerabsorbers, the heat input, and the desired refrigerating effect, so that a suitable amount of refrigerant is distilled off from the boiler-absorbers during each' heating period. overheating of the boiler-absorber should be avoided. It is an important feature of an apparatus in accordance with the invention that thel cycling depends upon a certain weight difference between the boilerabsorbers at the beginning and the end of a period. Due to this, the working conditions of the boilerabsorbers will always be stabilized, and the temperature interval of the boiler-absorbers will automatically accommodate itself to varying external conditions.

Figure 3 shows a single absorption system operating under the control of the weight variation of the boiler-absorber. A boiler-absorber 40 is provided with a central tube 4| surrounded by an intermediate tube forming a cooling pocket 42, flanges 43 carrying the absorbent being disposed on said intermediate tube. The boiler is connected with a counterweight 44 the system balancing on an edge 45.v 'Ihe boiler-absorber communicates with a condenser 54 and an evaporator 55 through a pipe 46, which in a portion of its length forms 'a spiral or a loop 41 for the purpose of increasing its flexibility. 'Ihe boilerabsorber is heated by means of an electric heating element 48 the electric current passing a mercury switch 49` placed on-the balance and participating in its movement. The cooling pocket 42 communicates through the pipe 50 with a separate condenser I cooled by flanges 52. The separate condenser may alternatively be cooled by cooling water, in which case the water conduit should be connected with the water main by means of flexible conduits such as rubber hose or the like. The separate secondary cooling system is filled with a limited amount of volatile liquid that all of the liquid can be stored in the condenser during the heating period.

The apparatus operates in the following manner. It is assumed that the movable system is tilted to the left, i. e. the boiler-absorber is in position to be heated. The volatile liquid is stored in the condenser 5I, and the cooling pocket is empty. Heating of the boiler-absorber will cause refrigerant to be expelled therefrom, which will condense in the condenser and flow into the evaporator 55; Whena predetermined amount of refrigerant has been liberated, the Weight of the boiler-absorber will have been lowered sufficiently to cause the balance to tilt towards the right. The

weight limits of the boiler-absorber during each `to the boiler-absorber.

period can be adjusted by varying the angle of tilting by means of the adjusting device 53 and by altering the position of the counterweight. When the balance is tilted towards the right, the electric current is switched off, and the separate secondary cooling system is put into action, whereby the boiler-absorber is quickly cooled and the absorption begins. At the end of the absorption period the balance will again be automatically reversed, to the left, and the heating period begins anew. The length of the absorption period depends upon the cold requirements, i. e. the rate of absorption. 'I'he quantity of cold per period is fairly constant, as always the same total amount of refrigerant is required to cycle back and forth The minor 'variations which will occur, are due to condensate temperature losses. The cooling effect of the apparatus per hour-can be governed by means of an ordinary electric thermostat disposed in the electric circuit comprising the mercury switch. This thermostat will turn off 'the current (or the gas if gas heating is used) independent of the reversing switch, so that the initiation of the heating periods are more or less delayed. It is also possible to use a multiple step heating element so that the thermostat will select that step which corresponds to the demand.

Figure 4 shows a modified design of a separate secondary cooling system in conjunction with two coordinated absorption systems. The main difference relative to the systems shown in Figures l and 2 and 3 lies with the method of circulating the volatile liquid in the separate cooling system. In the cooling system described in Figures l, 2, and 3, the communication between the secondary condenser, and each cooling pocket is brought about by means of only one comparatively heavy conduit, in' which gaseous and liquid medium pass in opposite directions during the cooling period. In Figure 4 the cooling pockets of the boiler-absorbers 60 and 6| are each communicating with the condenser 62 by two narrow conduits, pipes 63 and 64 respectively leading condensate to the lower ends of cooling pockets 61 and 68 to be Dcooled, and pipes 65 and 66 respectivelyforming a passage for the gasied fluid from the cooling pockets. The operation of the apparatus is in all other respects analogous to that described in con- Junction with Figures 1 and 2.

Other possible modifications, falling within the .scopeof the invention will be obvious to those said boiler-absorber, and connected to form a' circuit for heat transfer fluid in which liquid fluid can flow to said heat absorbing member from said heat dissipating member when said boilerabsorber is in one position but not when it is in another.

2. Absorption refrigeration apparatus including a boiler-absorber, a vaporization-condensation member having a vaporization portion in thermal transfer 'relation with said boiler-absorber, said boiler-absorber being constructed and arranged to move up and down in a substantially vertical plane in accordance with variation in positions in accordance with variation in weights i may flow by gravity from said heat ldissipating of fluid therein,- said heat dissipating member and wheat absorbing members being constructed and arranged to be moved responsive to movement of said boiler-absorbers, and each of said heat absorbing members being connected to said heat dissipating member to form circuits for heat transfer uid having said heat dissipating mem'- ber in common, and in which lcircuits liquid fluid member to,but one of said heat absorbing members in one relative position of said boiler-absorbers vand only to another of said members in another relative position ofsaid boiler-absorbers. I 4. Absorption refrigeration apparatus includ-` ing a plurality of boiler-absorbers, Aa vaporlzation-condensation member having -vaporization portions each in heat transfer relation with one of said boiler-absorbers, said boiler-absorbers being constructed'and arranged vto alter their rela'- tive positions in accordance `with variation in weights of iiuid therein, and said member being constructed and arranged so that liquid may flow to but one of said vaporization portions in one relative position of said boiler-absorbers and only to another of said vaporization portions in another relative position of said boiler-absorbers.

5.' Absorption refrigeration 'apparatus including two boiler-absorbers, a vaporization-condensation member havingtwc "vaporization portions each in heat transfer relation with one of said boiler-absorbers, said boiler-absorbers being constructed and arranged to alter their relative positions in accordance with variation in weights of `fluid therein, and means -for preventing ilow of liquid to one or the other of said vaporization portions responsive to'alteration in the relative position of said boilerabsorbers.

'moan 'm'vma mms HYLANDER. 

